Pallets of various types are known in the art. Pallets are typically constructed with parallel stringers to which transverse deck boards are then nailed or otherwise secured to form the pallet. Pallets need to have sufficient strength to bear the weight of objects loaded thereon, including other pallets, and to withstand such impact forces to which the pallets are subjected when objects are loaded onto and off of them and when the pallets are moved, as by a fork-lift truck or the like. Pallets must also withstand other external forces from their environment.
Typical pallets are constructed of wooden stringers and deck boards which are attached with nails or other metal fastener devices.
Many pallets sustain damage at their lead boards. As a fork lift or other mechanism engages a pallet, the mechanism will often impact the lead board of the pallet, sometimes with significant force. This shearing force may disengage the lead board or otherwise damage it, leaving a worn or weakened pallet with a lessened carrying capacity. Such damaged pallets are at greater risk of failure and greater risk of damage to merchandise and individuals.
Nails or other metal fastener devices are often used to construct pallets, but pallets can be damaged at the locations where the metal fastener devices attach to the wooden parts of the pallets. Such metal fasteners can gouge the wooden portions or create stress fractures in them. These conditions may weaken the pallets, promote their deterioration, and render them inoperable or dangerous to use.
Some fasteners protrude from the wooden boards, either by design or by accident. Where such fasteners protrude, those protrusions may be subjected to impact force from fork lifts or other devices, or forces from other random contact to the pallet. Such protrusions may also impact neighboring pallets, inflicting impact forces on neighboring pallets in addition to suffering impact forces themselves.
Where such protrusions possess sharp edges, those sharp edges may be particularly prone to suffering or inflicting impact forces. Further, such sharp edges may catch on other objects that contact the pallets, resulting in damage to the fasteners, or causing the fasteners to be loosened or pulled free from the pallets. Similarly, such sharp edges can further gouge neighboring pallets, structures, or individuals.
To save money and resources, worn or damaged pallets are often salvaged, with the undamaged portions used to make recycled pallets and the damaged portions put to other uses, such as fuel or sawdust. The cost and effort required to disassemble worn-out pallets increases when the pallets include metal pieces (i.e., nails or metal supports), as many devices that can be routinely used to break down wooden components cannot be used where there are also metal components. For example, standard saws or similar devices effectively cut through wooden boards, but not metal nails.
The devices that are suitable for disassembling wooden pallets having metal fasteners are often large, expensive, and unwieldy to use. These devices often fail to remove all metal fasteners from the wooden components, requiring additional efforts, as well as increased time and cost, to remove such fasteners before the wooden components can be reused.
Further, recycling efforts may require the segregation of waste materials by type; where the pallets are made of both wooden and metal components, additional time and effort may be required to sort the components before recycling them.
More recently, companies who utilize pallets have turned to Radio Frequency Identification (“RFID”) technology to monitor and track pallet location and other information. To use such technology, encoded RFID tags or devices are placed on a pallet. However, there have been problems implementing RFID systems, such as metal components interfering with the transmission of signals between RFID tags and RFID readers. Thus, a pallet free of metal parts (e.g., metal fasteners) is particularly advantageous in facilitating the use of RFID technology in conjunction with pallets and their cargo.
Further, metallic fasteners can damage wooden pallets by causing cracking and damage to the wooden components during construction. This problem is particularly pronounced when drier woods are used in the construction of wooden pallets.
However, the construction of metal-free pallets has been problematic. Pallets that rely on adhesives as the sole connecting means between deck boards and stringers have proven vulnerable to shear forces, random blows, and other forces typically sustained by a pallet during its assembly and use. Such pallets often require external clamps or other devices for configuring and holding the pieces together while the adhesive cures. Further, it takes a great deal of time to configure and make such pallets.
Pallets that incorporate either metal nails or wooden dowels to connect the stringers to the deck boards have also suffered problems. The insertion of such fasteners may exert shear forces on the deck boards and stringers during assembly. Further, protruding fasteners may contain sharp edges that may be susceptible to damage by shear forces, or may be loosened or pulled out, when caught on other external structures. Also, shear forces and other typical forces may introduce or exacerbate shear fractures in the deck boards and stringers.
There exists a need for a pallet that can be readily and economically assembled, can withstand substantial impact and load forces, can be easily disassembled, including with dry wood, and will not interfere with RF signals or prevent RFID readers from operating properly.